Asian Gypsy Moths

Can we recognize them when we see them?

Are the above 'native' North American or foreign imports?

What is the gypsy moth discrimination problem?

The three stages of the gypsy moth life cycle of which
concerned citizens are commonly
aware are the egg mass, the larva and the adult male.
The adult female is more rarely seen
because when it emerges from its pupa in the crotch of a
tree limb it remains close to the
pupal caste and starts emitting a pheromone which drifts with the breeze downwind signaling
males that there is a female upwind ready to mate. The stage which is most frequently
monitored by North American county, state and federal agencies is the adult male, which
can be lured during its mating flight to a trap using an
artificial female pheromone,
GYPLURE. Tens of thousands of these pheromone traps are set each summer.
The traps
call gypsy moth males from large distances, trapping them
and providing population biologists
inexpensive estimates of the surrounding gypsy moth population
size. It would be convenient
if this cheap, effective and well established monitoring program could be used to help us to
recognise when a foreign gypsy moth has entered our North American population.

Unfortunately, the males of the Asian, European and North American populations
are superficially indistinguishable. We are therefore unable to use trap data for easily
assessing the degree of the problem of incursion of the flying form of the gypsy moth
female into our North American population.

Projects are underway to allow the discrimination of the genetic origin of a male
gypsy moth using molecular biological approaches. These approaches may need
to be applied to the thousands of males trapped by local programs trying to contain
the spread of the Asian gypsy moth. We have developed a technique that allows
discrimination of Asian and European males from North American male gypsy moths
based on wing venation. This technique may be a cost effective way of pre-screening
the thousands of samples of male gypsy moths that may need to be analysed. If a
male wing is identified as potentially of Asian or European stock, it could be sent to
be analysed by the more difinitive molecular biological
screening procedures.

How do we do it?

We accomplish our goal by applying discriminant function analysis to
wing landmarks. We have established a database of expected wing landmark
variability for several North American, European and Asian populations. A male
Gypsy moth forewing of unknown origin is compared to this database and the
wing obtains a discriminant score assessing its likelihood of belonging to one
of the three origins we can recognise: North America, Europe or Asia. A higher
score for membership in one of the foreign databases marks a wing as being of
potential foreign origin.

The above approach uses established statistical concepts on a relatively
new type of morphological data, landmark coordinates. While landmark
coordinates have become a popular subject in the community of biologists
interested in biological shape,
our application of this approach is one of the first
cases in which it is being used to solve a practical problem. We need to explain
the general approach starting with its theoretical basis in order to make it
acceptable and, moreover, the method of choice in this arena of applied
technology. We also need to show examples of how this approach successfully
discriminates foreign gypsy moths from native gypsy moths.

How can you help this project?

If you are a citizen?

Become knowledgeable of the gypsy moth problem and cooperate with local
authorities in the diverse programs aimed at controlling the gypsy moth in your
area. Visit the Gypsy Moth Home Page.
If you think it is warranted, educate your local
legislators to the need for
further research to solve these problems.

If you are a gypsy moth researcher?

We need to upgrade our gypsy moth database with more specific
populations of gypsy moths. If you have access to collections of male
gypsy moths in your area, please contact our project to explore the
possibility of inclusion of your samples in our study. See how fast we
can add your population to the wing shape phenetic tree described above!
We are particularly interested in European and Asian populations but North
American populations from other gypsy moth strongholds in the USA, from
the advancing fringe away from the Northeast United States and isolated
populations from the Northwest United States are also needed.

If you have questions or potential contributions to our Gypsy Moth
Discrimination Project, you can send an
email message or snailmail message to Joe Kunkel, Biology
Department, University of Massachusetts, Amherst MA 01003.